import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;

public class ExplictTypeVarAnnos<E extends @Nullable Object, @Nullable F> {
    interface Consumer<A extends @Nullable Object> {}

    public static <B extends @Nullable Object> Consumer<B> cast(
            final @Nullable Consumer<? super B> consumer) {
        throw new RuntimeException();
    }

    public static <C extends @Nullable Object> Consumer<C> getConsumer0() {
        Consumer<@Nullable Object> nullConsumer = null;
        Consumer<C> result = ExplictTypeVarAnnos.<C>cast(nullConsumer);
        return result;
    }

    public static <@Nullable D> Consumer<D> getConsumer1() {
        Consumer<@Nullable Object> nullConsumer = null;
        Consumer<D> result = ExplictTypeVarAnnos.<D>cast(nullConsumer);
        return result;
    }

    public Consumer<E> getConsumer2() {
        Consumer<@Nullable Object> nullConsumer = null;
        Consumer<E> result = ExplictTypeVarAnnos.<E>cast(nullConsumer);
        return result;
    }

    public Consumer<F> getConsumer3() {
        Consumer<@Nullable Object> nullConsumer = null;
        Consumer<F> result = ExplictTypeVarAnnos.<F>cast(nullConsumer);
        return result;
    }

    @SuppressWarnings("method.invocation.invalid")
    Consumer<E> field = getConsumer2();

    public Consumer<E> getField() {
        return field;
    }

    static class A<Q extends @NonNull Object> {}

    // :: error: (type.argument.type.incompatible)
    static class B<S> extends A<S> {}
}
